1. Field of the Invention
The present invention relates to an air outlet device for a vehicle cabin (hereinafter referred to as “vehicle-cabin air outlet device”), for a center register, a side register, a lower register, a side defroster, or the like.
2. Description of the Related Art
Conventionally, there exists a vehicle-cabin air outlet device of a type which includes a tubular body which forms an air guide passage; a plurality of wind-direction adjustment plates (directional vanes) rotatably supported inside the tubular body and adapted to open and close an outlet opening at a front end of the tubular body; and a connection member which connects the wind-direction adjustment plates together and rotates them in an interlocked manner. The air outlet device has a wind distribution function of opening the outlet opening of the tubular body and adjusting the flow direction of blown air, and a wind shutoff function of closing the outlet opening of the tubular body to thereby stop the blowing of air. These functions are realized by rotating and adjusting the wind-direction adjustment plates between a parallel condition in which the plates become generally parallel to the axis of the tubular body and a serial condition in which the plates become generally perpendicular to the axis of the tubular body. A patent application has been filed for one form of such a vehicle-cabin air outlet device (see Japanese Patent Application Laid-Open (kokai) No. 2000-203254.
The vehicle-cabin air outlet device proposed in the patent application has three wind-direction adjustment plates, which are all connected with one another. Specifically, in the vehicle-cabin air outlet device, the wind-direction adjustment plates, which are rotatably supported inside a cylindrical tubular body, are connected with one another via a connection member, so that all the wind-direction adjustment plates rotate in an interlocked manner.
In the vehicle-cabin air outlet device, when the wind-direction adjustment plates are in the serial condition in which the plates become generally perpendicular to the axis of the tubular body, the wind-direction adjustment plates close an opening (the outlet opening) at the front end of the tubular body to thereby achieve the wind shutoff function. When a vehicle occupant pushes one of the wind-direction adjustment plates in this condition toward the interior of the tubular body, all the wind-direction adjustment plates rotate about respective rotation centers in an interlocked manner, and, at maximum rotation, rotate until the wind-direction adjustment plates enter the parallel condition in which the plates become generally parallel to the axis of the tubular body. Accordingly, the vehicle-cabin air outlet device allows the vehicle occupant to adjust the wind direction to a desired direction by use of the wind-direction adjustment plates; i.e., by rotating the wind-direction adjustment plates and adequately adjusting the amount of rotation.
As described above, in the vehicle-cabin air outlet device, through adjustment of the wind-direction adjustment plates; i.e., through adequate adjustment of the rotational amount of all the wind-direction adjustment plates in the parallel condition, the outlet opening at the front end of the tubular body can be opened, and the wind direction; i.e., the flow direction of air (wind) blown out of the outlet opening, can be adjusted. However, in this case, a clearance is naturally formed between the inner wall surface of the tubular body and the tip end edge of a wind-direction adjustment plate located on one side, and airflow comes out from the clearance. The airflow, which is influenced by the inner wall surface of the tubular body, goes straight and parallel to the axis of the tubular body, and changes the wind direction adjusted by the action of the wind-direction adjustment plates. That is, the airflow going straight out of the opening at the front end of the tubular body prevents the flow of air produced by means of the wind-direction adjustment plates. In such a case, the adjusted wind direction is changed from the wind direction desired by the vehicle occupant.
In the vehicle-cabin air outlet device, the above-mentioned clearance is unavoidably formed as a result of rotation of the wind-direction adjustment plates, and gradually increases with rotation of the wind-direction adjustment plates. Since the tip end edge of the wind-direction adjustment plate located on one side gradually separates apart from the inner wall surface of the tubular body when it rotates so as to open the outlet opening of the tubular body, formation of the above-mentioned clearance is unavoidable.